Effectiveness of Transcranial Alternating Current Stimulation (tACS) in Patients Having Insomnia Symptoms: A Systematic Review and Meta-analysis
Saad Arsalan Wasti1, Ali Akram Qureshi1, Maria Qadri2, Zainab Alvi1, Azka Ijaz1, Hammad Naveed1, Muhammad Waqas Bin Waheed1, Erum Habib3, Muhammad Usman Iqbal1, Muhammad Nabeel Saddique1, Muhammad Moiz Javed4
1King Edward Medical University, 2Jinnah Sindh Medical University, 3Dow University of Health Sciences, 4Geisinger College of Health Sciences
Objective:
To assess the effectiveness of transcranial alternating current stimulation in patients having insomnia symptoms.
Background:
Insomnia is a common sleep disorder that affects 10% of people worldwide, impairing daily functioning, reducing quality of life, and potentially leading to chronic cognitive impairment. Transcranial alternating current stimulation (tACS) is a novel, non-invasive, and non-pharmacological intervention that may offer benefits in treating insomnia.
Design/Methods:
We systematically searched PubMed, Scopus, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases from inception to May 2025 for relevant studies. Dichotomous outcomes were pooled as risk ratios (RR) and continuous outcomes as mean difference (MD) with 95% confidence intervals (CIs) using random-effects. The I2 and χ2 statistics were employed to evaluate inter-study heterogeneity. A P-value of <0.05 was considered statistically significant. All the calculations were performed using RevMan Web.
Results:
Five RCTs involving 369 participants were included (mean ages 48.6±14.7 to 55.3±8.0 years, 74.5% female). Most studies used daytime tACS sessions (20-40 min), targeting frontal or mastoid regions. Meta-analysis showed that tACS significantly improved global sleep quality, with reduced Pittsburgh Sleep Quality Index (PSQI) scores (MD -3.33; 95% CI: [-6.20 to -0.46]), sleep onset latency (MD -29.16 minutes; 95% CI: [-50.37 to -7.94]), total sleep time (MD 0.93 hours; 95% CI: [0.29 to 1.58]), sleep quality (MD -1.10; 95% CI: [-1.71 to -0.48]), and response rate (RR 7.45; 95% CI: [1.37-40.64]). Non-significant effects were found for Insomnia Severity Index (ISI), Hamilton Anxiety Rating (HAMA), Hamilton Depression Rating (HAMD) scores, sleep efficiency, or daily disturbances. Heterogeneity was high across outcomes.
Conclusions:
tACS may help improve sleep quality and latency in insomnia, though more rigorous, standardized, and larger-sample trials are needed to confirm benefits.
Disclaimer: Abstracts were not reviewed by Neurology® and do not reflect the views of Neurology® editors or staff.